Inhibition of IκB kinase by thalidomide increases hepatitis C virus RNA replication

Efficacy and safety of thalidomide in preventing oral mucositis in patients with nasopharyngeal carcinoma undergoing concurrent chemoradiotherapy: A multicenter, open-label, randomized controlled trial

BACKGROUND

This multicenter clinical trial was designed to evaluate the efficacy and safety of thalidomide (THD) in preventing oral mucositis (OM) in patients with nasopharyngeal carcinoma (NPC) undergoing concurrent chemoradiotherapy (CCRT).

METHODS

Patients with locally advanced NPC were randomly assigned to either a THD group or a control group. All 160 patients received radical intensity-modulated radiotherapy plus cisplatin-based concurrent chemotherapy and basic oral hygiene guidance. Patients in the THD group received additional THD at the beginning of CCRT. The primary end points were the latency period and the incidence of OM. The secondary end points were mouth and throat soreness (MTS), weight loss, short-term efficacy, and adverse events.

RESULTS

The median latency period of OM was 30 and 14 days in the THD and control groups, respectively (hazard ratio, 0.32; 95% confidence interval, 0.23-0.35; P < .0001). The incidence of OM and severe OM (World Health Organization grade 3 or higher) was significantly lower in the THD group than the control group (87.5% vs 97.5% [P = .016] and 27.5% vs 46.3% [P = .014], respectively). THD treatment also remarkably reduced the intensity of MTS and the degree of weight loss. In comparison with the control group, the incidence of nausea, vomiting, and insomnia was significantly decreased, whereas the incidence of dizziness and constipation was obviously increased in the THD group. The objective response rates 3 months after CCRT were similar between the groups.

CONCLUSIONS

THD prolonged the latency period, reduced the incidence of OM, and did not affect the short-term efficacy of CCRT in patients with NPC.

LAY SUMMARY

Oral mucositis is the most common complication of nasopharyngeal carcinoma during chemoradiotherapy; it decreases the patient's quality of life, and ideal mucosal protective agents are lacking. A few basic research and preclinical studies have shown that thalidomide may be an approach to ameliorating oral mucositis. The results of the current study confirm that thalidomide has a protective effect against oral mucositis in patients who have received chemoradiotherapy for nasopharyngeal carcinoma.

The clinical impact of hepatitis C virus infection in Egyptian multiple myeloma patients

BACKGROUND

Multiple myeloma (MM) is a human B cell neoplasia characterized by the clonal proliferation of malignant plasma cells in the bone marrow. Worldwide, hepatitis C virus (HCV) infection is a public health problem. For MM patients, the clinical impact of preexisting HCV infection is still unclear. We aim to assess the clinical characteristics and the prevalence of the HCV infection in Egyptian MM patients. This observational study included 81 MM patients. HCV antibody assay was performed, and positive cases were confirmed using a reverse transcription-quantitative PCR (RT-PCR) method.

RESULTS

Fifteen (18.5%) patients were anti-HCV antibody positive. Only 6/15 (7.4%) patients were HCV RNA positive by RT-PCR. Liver affection in the form of hyperbilirubinemia with grade 4 adverse events was significantly higher in the anti-HCV positive/HCV RNA positive group versus anti HCV negative group (16.7% vs. 1.5%, p value = 0.005). The median HCV-RNA before the initiation of chemotherapy was 2.5 log IU/ml with mean ± SD = 4.25 ± 1.6 with no HCV reactivation. In the univariate and multivariate analysis, HCV infection was not an independent factor related to DFS. Low hemoglobin level < 10 g/dL (HR 0.59, 95% CI, 0.36-0.97, p value = 0.037) and abnormal serum total bilirubin level (HR 1.9, 95% CI 1.03-3.5, p value = 0.039) influenced DFS in the univariate analysis. However, in the multivariate analysis, serum calcium level greater than 12 mg/dL (HR 7.04, 95% CI 1.12-44.45, p value = 0.038) and abnormal serum total bilirubin level (HR 10.9, 95% CI 2.92-41.02, p value = < 0.001) remained statistically significant worse prognostic factors.

CONCLUSION

In conclusion, our study revealed the prevalence of HCV infection in Egyptian MM patients. Serologic tests at diagnosis are necessary to identify these patients, and confirmation of positive cases by molecular techniques should be mandatory, with regular follow-up for liver dysfunction. Finally, further larger studies explaining the molecular mechanisms linking HCV and the MM pathogenesis are warranted.

mTORC1 restricts hepatitis C virus RNA replication through ULK1-mediated suppression of miR-122 and facilitates post-replication events

The mechanistic target of rapamycin (mTOR), an important kinase that assimilates several upstream signals, associates into two functional complexes, mTORC1 and mTORC2. In this study, we demonstrate that HCV infection activates mTORC1 that functions in important antiviral response. Pharmacological inhibition of mTOR complexes augmented cellular HCV RNA levels, the observation confirmed further by Raptor depletion, indicating antiviral roles of mTORC1. ULK1 depletion phenocopied mTOR inhibition and thus suggested that mTORC1 restricts HCV replication through ULK1. We reveal that ULK1 depletion augmented the levels of miR-122, a critical host factor for HCV replication, thus possibly regulating HCV replication. The increase in HCV RNA levels, however, failed to augment intracellular infectious virion production, reflecting a lower rate of virion assembly. Higher intracellular HCV RNA levels, however, did not result in a corresponding increase in HCV RNA and infectious titres in mTOR inhibited supernatants, but in contrast showed a consistent drop, confirming defective viral assembly caused by the inhibition. Consistent with this, the mTOR activator caused a significant drop in HCV RNA levels both in infected cells and in the supernatant. Our results demonstrate that ULK1 depletion did not affect autophagy, suggesting that ULK1-mediated HCV regulation is autophagy independent. Together, our data demonstrate that mTORC1 functions to suppress HCV RNA replication, but facilitates the virion packaging and release. Our studies reveal that the activation of mTOR by HCV infection is an antiviral measure by the cells.

Hepatitis C virus infection and risk of multiple myeloma: Evidence from a meta-analysis based on 17 case-control studies

Hepatitis C virus (HCV) infection is a leading cause of chronic liver damage and is associated with other diseases. Some studies reported that patients with HCV have a significantly increased risk of multiple myeloma while others do not report an association. We aimed to clarify the association between HCV and multiple myeloma and analyse the factors that affect the controversial conclusions through a meta-analysis. We conducted a systematic literature search of HCV and myeloma in the databases of PubMed/MEDLINE, Cochrane Library, EMBASE, Wanfang and China National Knowledge Infrastructure (CNKI) from inception to September 2016. Outcomes were expressed as odds ratios (ORs) and 95% confidence intervals (95% CIs). A positive correlation between HCV infection and risk of developing multiple myeloma was revealed (OR=2.67, 95% CI=1.35-5.26, P=.005) based on meta-analysis of 17 case-control observational studies. When the data were stratified by source of control, significant associations were observed in hospital-based studies, but not population-based studies. Further subgroup analyses showed increased risk of multiple myeloma in HCV patients when studies were conducted in high HCV prevalent countries, but not in low or moderate HCV prevalent countries. In addition, similar positive association was detected in studies performed in the East Asia and in intermediate-quality studies. In summary, the association of HCV infection with increased risk of multiple myeloma depended on several factors, including study design, quality and environmental HCV prevalence. Further large-scale, well-designed studies are needed to validate the role of HCV in the aetiology of multiple myeloma.

Management of Multiple Myeloma Complicated by Hepatitis C Virus Reactivation: The Role of New Antiviral Therapy

Reactivation of chronic hepatitis C virus (HCV) infection has been reported in cancer patients receiving chemotherapy. In this study, we report the first case, to our knowledge, of thalidomide-induced acute exacerbation and reactivation of chronic HCV infection complicating management of multiple myeloma. Sofosbuvir-based antiviral therapy helped achieve viral clearance and normalization of liver enzymes, thus allowing access to future potentially life-saving chemotherapy agents.

Hepatitis C virus-mediated Aurora B kinase inhibition modulates inflammatory pathway and viral infectivity

BACKGROUND & AIMS

Chronic hepatitis C is a leading cause of chronic liver disease, cirrhosis and hepatocellular carcinoma. DNA methylation and histone covalent modifications constitute crucial mechanisms of genomic instability in human disease, including liver fibrosis and hepatocellular carcinoma. The present work studies the consequences of HCV-induced histone modifications in early stages of infection.

METHODS

Human primary hepatocytes and HuH7.5 cells were transiently transfected with the core protein of hepatitis C virus (HCV) genotypes 1a, 1b, and 2a. Infectious genotype 2a HCV in culture was also used.

RESULTS

We show that HCV and core protein inhibit the phosphorylation of Serine 10 in histone 3. The inhibition is due to the direct interaction between HCV core and Aurora B kinase (AURKB) that results in a decrease of AURKB activity. HCV and core significantly downregulate NF-κB and COX-2 transcription, two proteins with anti-apoptotic and proliferative effects implicated in the control of the inflammatory response. AURKB depletion reduced HCV and core repression of NF-κB and COX-2 gene transcription and AURKB overexpression reversed the viral effect. AURKB abrogation increased HCV specific infectivity which was decreased when AURKB was overexpressed.

CONCLUSIONS

The core-mediated decrease of AURKB activity may play a role in the inflammatory pathway during the initial steps of viral infection, while ensuring HCV infectivity.

The roles of endoplasmic reticulum overload response induced by HCV and NS4B protein in human hepatocyte viability and virus replication

Hepatitis C virus (HCV) replication is associated with endoplasmic reticulum (ER) and its infection triggers ER stress. In response to ER stress, ER overload response (EOR) can be activated, which involves the release of Ca²⁺ from ER, production of reactive oxygen species (ROS) and activation of nuclear factor κB (NF-κB). We have previously reported that HCV NS4B expression activates NF-κB via EOR-Ca²⁺-ROS pathway. Here, we showed that NS4B expression and HCV infection activated cancer-related NF-κB signaling pathway and induced the expression of cancer-related NF-κB target genes via EOR-Ca²⁺-ROS pathway. Moreover, we found that HCV-activated EOR-Ca²⁺-ROS pathway had profound effects on host cell viability and HCV replication. HCV infection induced human hepatocyte death by EOR-Ca²⁺-ROS pathway, whereas activation of EOR-Ca²⁺-ROS-NF-κB pathway increased the cell viability. Meanwhile, EOR-Ca²⁺-ROS-NF-κB pathway inhibited acute HCV replication, which could alleviate the detrimental effect of HCV on cell viability and enhance chronic HCV infection. Together, our findings provide new insights into the functions of EOR-Ca²⁺-ROS-NF-κB pathway in natural HCV replication and pathogenesis.

Glutathione during embryonic development

BACKGROUND

Glutathione (GSH) is a ubiquitous, non-protein biothiol in cells. It plays a variety of roles in detoxification, redox regulation and cellular signaling. Many processes that can be regulated through GSH are critical to developing systems and include cellular proliferation, differentiation and apoptosis. Understanding how GSH functions in these aspects can provide insight into how GSH regulates development and how during periods of GSH imbalance how these processes are perturbed to cause malformation, behavioral deficits or embryonic death.

SCOPE OF REVIEW

Here, we review the GSH system as it relates to events critical for normal embryonic development and differentiation.

MAJOR CONCLUSIONS

This review demonstrates the roles of GSH extend beyond its role as an antioxidant but rather GSH acts as a mediator of numerous processes through its ability to undergo reversible oxidation with cysteine residues in various protein targets. Shifts in GSH redox potential cause an increase in S-glutathionylation of proteins to change their activity. As such, redox potential shifts can act to modify protein function on a possible longer term basis. A broad group of targets such as kinases, phosphatases and transcription factors, all critical to developmental signaling, is discussed.

GENERAL SIGNIFICANCE

Glutathione regulation of redox-sensitive events is an overlying theme during embryonic development and cellular differentiation. Various stresses can change GSH redox states, we strive to determine developmental stages of redox sensitivity where insults may have the most impactful damaging effect. In turn, this will allow for better therapeutic interventions and preservation of normal developmental signaling. This article is part of a Special Issue entitled Redox regulation of differentiation and de-differentiation.

Mechanism of immunomodulatory drugs' action in the treatment of multiple myeloma

Although immunomodulatory drugs (IMiDs), such as thalidomide, lenalidomide, and pomalidomide, are widely used in the treatment of multiple myeloma (MM), the molecular mechanism of IMiDs' action is largely unknown. In this review, we will summarize recent advances in the application of IMiDs in MM cancer treatment as well as their effects on immunomodulatory activities, anti-angiogenic activities, intervention of cell surface adhesion molecules between myeloma cells and bone marrow stromal cells, anti-inflammatory activities, anti-proliferation, pro-apoptotic effects, cell cycle arrest, and inhibition of cell migration and metastasis. In addition, the potential IMiDs' target protein, IMiDs' target protein's functional role, and the potential molecular mechanisms of IMiDs resistance will be discussed. We wish, by presentation of our naive discussion, that this review article will facilitate further investigation in these fields.